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#1080
by
ChrisGebhardt
on 09 Oct, 2007 02:26
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How many Ice Frost Ramps are present on the External Tank?
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#1081
by
usn_skwerl
on 09 Oct, 2007 17:55
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we all know the shuttle cant get out of LEO. with little more than 7 crew, a satellite cradle, and the RMS, what is the maximum possible altitude the shuttle can get to if absolutely necessary, if required to do some necessary maintenance to a satellite, something like the hubble servicing missions?
are there still servicing points within the cargo bay that still allow hookup of LOX and LH2? i think i remember there being something like that back in the 80's?
thanks.
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#1082
by
DaveS
on 09 Oct, 2007 17:58
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usn_skwerl - 9/10/2007 7:55 PM
are there still servicing points within the cargo bay that still allow hookup of LOX and LH2? i think i remember there being something like that back in the 80's?
You're thinking about the umbilical system for the Centaur upperstage. That has been since long removed. And only Atlantis, Discovery and Challenger was modified to support it. The Extended Duration Orbiter(EDO) cryokit was loaded the same way that the fuel cell reactant storage spheres are loaded: through the Orbiter Mid-Body Umbilical Unit(OMBUU).
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#1083
by
Chris Bergin
on 09 Oct, 2007 18:09
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Moved:
Real Madrid - 9/10/2007 6:56 PM
and what happens as a crewmember are sick ?
From STS-4 onwards, NASA halted the appointment and training of complete backup flight crews. Instead, individual flight crew members may have designated backups who could take their place within the prime crew. The decision on whether to appoint a reserve crew member is made on a per-flight basis by flight management teams at Johnson Space Center. Consequently, the last NASA flight crew to have a full-time backup crew was STS-3.
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#1084
by
Jorge
on 09 Oct, 2007 18:11
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MKremer - 7/10/2007 4:34 PM
Jim's reply is probably correct - no real reason since it wasn't designed to gain lift and take off from a horizontal runway. The only reason I can think of to have the nose gear a bit longer is to make for a bit gentler touchdown at the front end before the control surfaces lose most of their effect and drop the nose onto the runway.
There is one other reason to have a longer nose gear strut: the negative angle of attack resulting from the shorter nose gear increases loads on the
main gear as the nose gear derotates and slaps down. Buran had a longer nose gear strut for this reason. The Soviets had to design the crew compartment differently to accommodate this, so retrofitting the Buran design onto the shuttle is not practical. But a telescoping nose gear strut has been proposed from time to time as an orbiter upgrade.
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#1085
by
Jorge
on 09 Oct, 2007 18:15
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usn_skwerl - 9/10/2007 12:55 PM
we all know the shuttle cant get out of LEO. with little more than 7 crew, a satellite cradle, and the RMS, what is the maximum possible altitude the shuttle can get to if absolutely necessary, if required to do some necessary maintenance to a satellite, something like the hubble servicing missions?
Not much higher than the highest Hubble missions (~340 n.mi.). On Hubble missions, the orbiter spends practically half its OMS propellant on the OMS-2 burn, and the other half on deorbit. There isn't a whole lot of margin to increase the orbit further. The payload bay for Hubble missions doesn't have much more than the necessary RMS, airlock, Hubble FSS (cradle), and Hubble servicing hardware.
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#1086
by
Jim
on 09 Oct, 2007 19:35
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usn_skwerl - 9/10/2007 1:55 PM
we all know the shuttle cant get out of LEO. with little more than 7 crew, a satellite cradle, and the RMS, what is the maximum possible altitude the shuttle can get to if absolutely necessary, if required to do some necessary maintenance to a satellite, something like the hubble servicing missions?
thanks.
It is in an earlier post on this thread
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#1087
by
usn_skwerl
on 09 Oct, 2007 22:32
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yes, i found it now, but you DO realize that there are well over 170 pages of shuttle Q & A to wade through, even using search.
besides, i was also accounting for the (now deleted) cargo bay access points being factored in for a little extra deltaV and altitude.
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#1088
by
Jim
on 09 Oct, 2007 22:42
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usn_skwerl - 9/10/2007 6:32 PM
yes, i found it now, but you DO realize that there are well over 170 pages of shuttle Q & A to wade through, even using search.
besides, i was also accounting for the (now deleted) cargo bay access points being factored in for a little extra deltaV and altitude.
The LH2 and LO2 acess point were not for the shuttle but for the centaur upperstage. This propellants were not available to the shuttle. You might be thinking of the OMS kits that would have been carried in the payload bay. They were never developed and Direct insertion provided the higher altitudes required
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#1089
by
usn_skwerl
on 10 Oct, 2007 02:52
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thanks jim, i thought it could feed the shuttle, not just pull from it. i kind of wondered how they'd apply cryo's to the RCS/OMS system....
ok, another one, maybe a little more difficult to answer.....
is there an animation or video of a SIMULATED RTLS sequence? i know the consequences and possible dangers of that evolution, but ive never seen a good visual of it, just a crappy sequential line drawing years ago in a library book
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#1090
by
Jim
on 10 Oct, 2007 11:10
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usn_skwerl - 9/10/2007 10:52 PM
thanks jim, i thought it could feed the shuttle, not just pull from it. i
The connection weren't to "pulled" propellant from the shuttle. They were feedthru's to ground connections to load the Centaur. There was no interconnection between the shuttle propulsion system and the LO2 and LH2 ducts in the payload bay. There was even a separate T-0 umbilical on the outside of the orbiter which fueled the centaur through the payload bay
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#1091
by
brahmanknight
on 10 Oct, 2007 15:44
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From the last article about STS 120 by Chris: "A few hours of contingency time remains, but that takes into account a cease to pad operations during the launch of the Atlas V carrying the Wideband Global SATCOM satellite Wednesday night."
Do operations cease in case the Atlas veers off course, or is it something else?
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#1092
by
Jim
on 10 Oct, 2007 16:07
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LC-39 is within the launch danger area (LDA) for the launch off SLC-41
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#1093
by
RafaelCE
on 12 Oct, 2007 16:17
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I have searched for the Hotfire term along the site. Only found refferences to the term but not an explanation of what that is. I've heard of RCS hotfire, APU hotfire, hotfire tests. etc. Can someone elaborate on what that is and how is performed?
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#1094
by
DaveS
on 12 Oct, 2007 16:30
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RafaelCE - 12/10/2007 6:17 PM
I have searched for the Hotfire term along the site. Only found refferences to the term but not an explanation of what that is. I've heard of RCS hotfire, APU hotfire, hotfire tests. etc. Can someone elaborate on what that is and how is performed?
RCS hotfire involves firing each and every one of the 44 RCS jets(38 primary, 6 verniers) to verify that they work OK for entry.
APU hotfire involves running all APUs at high speed setting for about a minute or so to verify their operation.
It all depends on what system is involved.
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#1095
by
Joffan
on 12 Oct, 2007 16:37
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Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
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#1096
by
DaveS
on 12 Oct, 2007 16:41
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Joffan - 12/10/2007 6:37 PM
Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
RCS hotfire tests are only done on-orbit on the day prior to planned de-orbit and landing.
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#1097
by
Jim
on 12 Oct, 2007 16:46
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Joffan - 12/10/2007 12:37 PM
Follow-up question... is there such a thing as a coldfire test? And would that be without propellants loaded, just testing valve actuation, or perhaps with an inert pressurised gas also testing flow?
Usually that is called a cold flow test.
(aerospace engineering) A test of a liquid rocket without firing it to check or verify the integrity of a propulsion subsystem, and to provide for the conditioning and flow of propellants (including tank pressurization, propellant loading, and propellant feeding).
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#1098
by
usn_skwerl
on 13 Oct, 2007 03:18
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where is the CG for the shuttle roughly when configured for reentry? for an external reference on the fuselage, is it typically somewhere between the Ensign and the "U" in "United States?" (when looking at port fuselage)
and at T-0, is the stack's CG usually between the orbiter and ET, and under the first joint of the payload bay door (simple diagram below)
Fwd (nose) |_____|_____|_____|____|Aft (tail)
CG at T-0?..........X........<~at point marked "X"?
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#1099
by
Jorge
on 13 Oct, 2007 04:31
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